Why do I need theSmartSet?

The tubing set pictured here is the 001.2 model, the 'Smartset with
sideport.  Our less expensive 'Smartset'(no sideport), model
001.4, does not have the small extra port located between the
clamp and the swivel lock.

Challenge of I.V. Tubing:

When we first starting injecting gadolinium contrast dynamically for MR angiography we immediately encountered
innumerable problems. Tubing connections came apart causing gadolinium to spray everywhere. Blood backed out of
the iv site where it disconnected from the pressure of the injection. Dead space within the iv tubing varied depending
upon exactly how the iv was set-up. Without knowing the dead space exactly it was impossible to know exactly when
the gadolinium reached the end of the iv tubing and began entering the patient. This increased the unpredictability of
bolus timing. Perhaps the greatest problem was switching from gadolinium contrast infusion to saline flush. Any delay
in beginning the saline flush created a gap in the bolus. If this gap coincided with acquisition of central k-space data
then it created ringing artifacts. If we used a 3-way stopcock, the rush to switch from gadolinium infusion to saline flush
inevitably occurred a little early so that not all of the gadolinium was injected. The waste of gadolinium was typically
2-3 ml which amounted to nearly $10 for every case, and in addition the image quality was not as good. Sometimes
flimsy iv tubing kinked when it got caught on the magnet or under the table when the patient was moved in and out of
the magnet. There was also great variation in the tubing resistance depending on the specific iv tubing, connections
and length used.

Advantage of the Smartset:

To solve these problems we began to experiment with various ways of hooking up iv tubing. Unfortunately none of the
intravenous tubing available was well suited for the purpose of dynamic gadolinium injections for liver, brest, or pelvic
MRI or MR Angiography. By working with several manufacturers we began to refine the design of an iv tubing system.
Over 100 iterations on the design have involved tubing lumen, resistance, wall thickness, type of connectors,
adaptability to different required lengths, one-handed operation, a valve assembly for automatic switching between
gadolinium contrast infusion and saline flush. We have now used this "SmartSet" for thousands of cases of dynamic
gadolinium contrast infusions for MR Angiography, liver MRI, breast MRI and other dynamic contrast injection with
universally favorable experience compared to the disastrous experience of assembling off the shelf components.
Because of this positive experience, we are now making this available to anyone who wants to perform dynamic MR
contrast injections by hand without having to repeat all the mistakes we made prior to developing the SmartSet.

Do I need a Power Injector?
We experimented with MR compatible contrast injectors and have not found them to be very useful. Injectors are
extremely useful in CT and conventional X-ray angiography so that technologists and radiologists do not have to be in
the room during X-irradiation of the patient. It adds an element of complexity to the injection process for the benefit of
reducing radiation exposure to personnel. With CT, large volumes of iodinated contrast need to be injected at high
rates, which could be difficult to do by hand. But in MRI, just like with ultrasound, there is no risk from being in the
room during scanning. Furthermore, the relatively smaller volume of dynamic gadolinium contrast injections is easy to
manage by hand injection. The Fourier nature of 3D spoiled gradient echo MRA data acquisition does not require the
constant, precise injection rate that is essential for CT and X-ray angiography. Three-dimensional MRA is acquired
with a single center of k-space that determines image contrast for the entire volume of data. Timing with respect to the
center of k-space is more important than having a constant, mechanically controlled injection rate.

Actually we not only found that injectors were not necessary, in many ways they were not as good as injecting by
hand. Injecting by hand made it easier to identify problems with the iv. Especially when using a tenuous iv in the hand
or wrist we were much more comfortable with hand injection. Power injectors tended to destroy the tenuous iv while
with hand injection, the operator discovers the problem in time to salvage the iv and avoid wasting gadolinium. For
patients with PICC or central lines or for pediatric patients, use of power injectors is forbidden because they can
explode central lines and damage delicate pediatric veins.  Also, standing next to the patient to perform hand
injections made it a lot easier to give the patient hyperventilation and breath holding instructions. In fact, the whole
process of coordinating contrast infusion, breath holding and activation of the scanner was much easier standing next
to the magnet with hand injection than from outside the magnet using the power injector. For these reasons, our
power injector sits idle in the corner of the room. The rare times when we actually use our power injector are for
research projects when we want to have a mechanically precise injection rate for experimental purposes.